grammar::peg::interp - Interpreter for parsing expression grammars
TABLE OF CONTENTS
SYNOPSIS
DESCRIPTION
THE INTERPRETER API
BUGS, IDEAS, FEEDBACK
KEYWORDS
COPYRIGHT
package require Tcl 8.4
package require grammar::mengine ?0.1?
package require grammar::peg::interp ?0.1?
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This package provides commands for the controlled matching of a character stream via a parsing expression grammar and the creation of an abstract syntax tree for the stream and partials.
It is built on top of the virtual machine provided by the package grammar::mengine and directly interprets the parsing expression grammar given to it. In other words, the grammar is not pre-compiled but used as is.
The grammar to be interpreted is taken from a container object following the interface specified by the package grammar::peg::container. Only the relevant parts are copied into the state of this package.
It should be noted that the package provides exactly one instance of the interpreter, and interpreting a second grammar requires the user to either abort or complete a running interpretation, or to put them into different Tcl interpreters.
Also of note is that the implementation assumes a pull-type handling of the input. In other words, the interpreter pulls characters from the input stream as it needs them. For usage in a push environment, i.e. where the environment pushes new characters as they come we have to put the engine into its own thread.
The package exports the following API
This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category grammar_peg of the Tcllib SF Trackers. Please also report any ideas for enhancements you may have for either package and/or documentation.
LL(k), TDPL, context-free languages, expression, grammar, matching, parsing, parsing expression, parsing expression grammar, push down automaton, recursive descent, state, top-down parsing languages, transducer, virtual machine
Copyright © 2005 Andreas Kupries <andreas_kupries@users.sourceforge.net>